Lightning arrester



Aug. 27. 1935.. E, A. EvERl-:TT 2,012,342

LIGHTNING ARRESTER -Fi'led Feb. 8, 1932 INVENTOR.

` ATTO Y Patented Aug. 27, 1935 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to lightning arresters, particularly of the resistox` type and has for an object to provide an arrester having a base supporting a stem with a porcelain sleeve; to provide a flanged base on a porcelain sleeve for a grounded stem of an arrester and, to provide an assembly of parts which facilitates manufacture and replacement. Other objects of the invention will be more particularly understood from the following specification and the accompanying drawing, in which, Fig. 1, is an elevation of an arrester, partly sectioned, and mounted on an insulating base embodying my invention; Fig. 2, is a plan view on line 2-2, Fig. l; Fig. 3, is a View on line with the porcelain sleeve; Fig. 5, is a plan View looking from the top of the base, Fig. 6 is a modification of the construction shown in Fig. 1, and Fig. l is a sectional detail. This invention comprises a lightning arrester mounted by terminal strips on the binding posts of a terminalblock. 'I'he arrester comprises a base, preferably of moulded insulation such as bakelite which has projecting wings on each side connecting to the terminal strips. This base is provided with a hollow core and a central aperture in which the grounding stem of the arrester is mounted. 'I'his stem is splined on a spider member which is imbedded in the insulation of the base so that when the member is secured in position it is rigidly supported on the base with a non-turning support. The stem is provided with a porcelain sleeve having a flange base at the lower end which rests in the core of the insulating base and insulates the stem from the conducting strips. It has been found in practice that the use of a porcelain sleeve on the stem is highly desirable and under the effect of con 'ginued lightning discharges does not materially change its characteristics.

In order to guard against the possibility of the porcelain sleeve becoming fractured, it is loosely mounted on the terminal stem and rests on a yieldable gasketv so that it is not influenced by temperature changes. 'I'he device is constructed to provide comparatively large spark gap surfaces between conducting parts and to facilitate the lightning discharge through a resistor block. This invention is an improvement upon the construction shown in my co-pending application Serial No. 494,164, filed Nov. 7, 1930.

In the drawing, I I is a terminal block on which the binding posts I2 and I3 are mounted. The

5 binding post I2 clamps the terminal strip I5 and 3--3 of Fig. 1; Fig. 4, is an elevation of the stem the binding post I3 clamps the terminal strip I6. The insulated base I9 is provided with grooves as indicated at 20, Fig. 5, and in one of these grooves the terminal strip I5 is secured by the eyelet Il and in the opposite groove the terminal strip 5 I6 is secured by the eyelet I8. The sides of the base are substantially flushed with the top of the strips I5 and I6.

The central post 2|, which is used for the ground connection through the terminal nuts I4 10 is secured to the base I9 by a splined connection as indicated at 24 with the spider 23, Fig. 3, which enters the corresponding depression 23a in the base and is fastened in position by the nut 22 through stem 2|. 'I'his provides a vertical nonturning stem in thev base I9 and enablesthe base to be moulded without the stem. The spider 23 is mounted in a depression on the raised ledge 25 of the base which is separated from the walls of the core as indicated at 26. 20

A gasket 21 of cork or other yieldable material is placed on the stem and between this gasket and the collar 30 the sleeve 29 is placed as shown. This sleeve is made from porcelain and has a anged base as indicated at 29 which is located 2 in the core of .the base I9. The stem is assembled as shown in Fig. 4 before it is secured to the base I9.

The resistor block 4I which is shown in the drawing as cylindrical in shape is placed on the 30 sleeve 29 and may be provided on the top with an insulated washer 42 of mica. This washer may be placed on the bottom or a washer may be placed on top and bottom if desired. The resistor block 4I is clamped upon the terminal strips I5 and I6 35 by the spring washer 43 which is clamped by the sleeve 44 on the stem 3| and which also engages the gasket 45 resting upon the cover 46, and securing the cylindrical transparent housing 41 on the gasket 48 for enclosing the resistor block. 40

The use of the insulated washer 42 is optional and is usually provided only when the lightning is to be shunted between the terminal strips I5 and I6, through the resistance block 4I. Its use secures a high insulation test to ground for line 45 Wires connected to the arrester. When the discharge from the terminal strips I 5 and I 6 is made through the resistance block 4I to the ground connection at I4, the washer 42 may be omitted.

One object of the construction is to encourage 50 the discharge of lightning over the outer surface of the block 4I and with this end in view the spring washer 43 engages the block 4I near its outer edge and the terminal strips I5 and I6 do not extend all the way in to the porcelain sleeve.

eiectivelvprevents lig tning discharging through the core of the lease i3 to the lower` end oi stem 2 i The discharge of .lightning in this direction is Y further prevented hv the annular depression it surrounding the ledge fit. Attention is called to the fact that as indicated Figs. 2, 5 and Z the base I9 is notched in the Walls of the core at 32a immediately below the discharging points Si of the terminal strips it and. it. It has heen found in practice that by thus increasing the surface of insulation'over which lightning has to discharge that it can be eilectivelv prevented from taking an undesirable path.

' For instance, in Fig. 7, the lightning indicated by a follows the surface and the V groove hut arcs across before reaching the ot the groove. This prevents this Dart ot the surface becoming oarloonized and 'tends to maintain the discharging conditions constant. l the groove were rectangular as indicated at this condition would not he secured.

In Fig. 6 the terminal strip i5 is provided with a Wing 5i pivots-ily connected thereto at 552 and the terminal strip iii has a corresponding Wing 53 pivotally connected at The wings or arms iii and enable the arrester to oe connected to terminals spaced different distances apart without disturbing the relation o the terminm strips l5 and i@ to the discharge loloclr lli.

Exhaustive tests :na-cle with this arrester show that it is capable of discharging lightning on loiv tension lines practically indefinitely Without losits effectiveness in discharging lightning and without lowering the normal resistance or the circuits which it is used to protect.

Having thus described my invention, l claim:

l. A lightning arrester comprising a condiren tor, a lease oi insulation having a core therein mounted on said conductor, a stern secured to said base, a porcelain sleeve mounted on said stern having a flange located in the core ot said hase engaged "ov said conductor, a resistor surrounding said sleeve having one tace engaging said conductor and means connecting the opposite tace of said resistor said stem.

2. a lightning arrester comprising a conductor, a base oi insulation mounted on said conductor, a stern secured to said tias-e, a porcelain sleeve loosely mounted on said stem, a yieldable gasket on said stern engaging said sleeve, a

resistor surrounding said sleeve and resting on said conductor, and spring Ameans connecting said resistor with said stern. l

3. A lightning arrester, comprising a conclue tor, a lease with a hollow core mounted on said conductor, a raised ledge on bottom ci said core,

. ing through the aperture in said st a spider, a groove on said ledge matching said spider, a stem splined to said spider, means for securing said stem to said hase, a sleeve of insulation on said stem, a resistor on said sleeve resting on said conductor and means connecting said resistor' with said stern.

e.. .a lightning arrester comprising a pair of fixed terminal strips, a base of insulation, grooved to receive said strips, a stem on said hase, resistor centered on said forming a connec-l tion between said stem and said strips and pivoted arms connected to said strips.

5. lightning arrester comprising a "pair of conducting strips having an aperture there lietvveen, a oase of insulation, strip-s mounted in a groove in said oase to leave an aperture therebetween, a. stern secured to said hase protestine through aperture, a sleeve on stein, discharging means connected cettveen said stern and said strip, an arm joivotally con nested to each of said strips.

6. il lightning arrester comprising a can tor, a base of insulation mounted on conm ductor having a core formelA therein, a stern seu cured to said base, a porcelain sleeve loosely mounted on said stern having its lower end lon cated in the core of the "oase 1esistor mounted on said sleeve in contact with s id con ductor and means connecting said resistor discharge relation with said stein.

7. A lightning arrester comprising tor strip with an aperture therein, insulation mounted on said strip, a to said hase, a porcelain sleeve said ster; 1

. gf' engaging one end of said sleeve and a collar on said stem engaging the other end oi sleeve,

and a resistor mounted on said sleeve foi patlror lightning between said stern nic conductor strip.

8. A lightning arrester comprising a conductor, a hase of insulation mounted on con-- ductor having a core with notches formed therein, said conductor extending in discharge points over the notches in said core, a stem. in said core, a porcelain sleeve on said stern, and a resistor bloei: mounted ou said sleeve :forming path for lightning between sai-d stein and said conductoru 9. A lightning arrester comprising a conductstrip having atomi-circular end, a base of insulation mounted on said strip, a stein secured to said loase, a porcelain sleeve on said stein conn centric with said semiMcircular end, a gasket engaging one end of said sleeve and collar on said stem engaging the other end or" said sleeve and a resistor mounted on said sleeve form.- ing a path for lightning between said stein and said conductor strip.

EDWARD lil 

